William Cavendish, 5th Duke of Devonshire

William Cavendish, 5th Duke of Devonshire (14 December 1748-29 July 1811) was Lord High Treasurer of Ireland from 13 March 1766 to 1793, succeeding William Cavendish, 4th Duke of Devonshire and preceding Richard Boyle, 2nd Earl of Shannon.

Biography
William Cavendish was born in 1748, the son of William Cavendish, 4th Duke of Devonshire. Like his father, he served as Lord High Treasurer from 1766 to 1793, and he married Georgina Cavendish, Duchess of Devonshire. Her affair with Charles Grey, 2nd Earl Grey and Cavendish's own affair with Georgina's friend Elizabeth Cavendish, Duchess of Devonshire almost led to the couple's divorce, but Georgina ultimately stayed with him until her death in 1806. William then remarried to Elizabeth, and he died in 1811.